photo-identification of the korea

Transcription

PHOTO-IDENTIFICATION OF THE
KOREA-OKHOTSK GRAY WHALE
(ESCHRICHTIUS ROBUSTUS)
POPULATION ALONG THE NORTHEAST
COAST OF SAKHALIN ISLAND, RUSSIA,
2003
Final Report
Prepared for:
Exxon Neftegas Ltd. and Sakhalin Energy Investment Company Ltd.
Yuzhno-Sakhalinsk
Russia
Prepared by:
Yuri Yakovlev and Olga Tyurneva
June 2004
TABLE OF CONTENTS
STUDY PARTICIPANTS AND AFFILIATIONS ............................................................ II
ACKNOWLEDGMENTS .................................................................................................III
LIST OF FIGURES ...........................................................................................................IV
LIST OF TABLES.............................................................................................................IV
INTRODUCTION ...............................................................................................................1
OBJECTIVES ......................................................................................................................2
BACKGROUND .................................................................................................................3
METHODS ..........................................................................................................................6
Study Area ........................................................................................................................6
Field Photo-id ...................................................................................................................6
Photo and Video Analysis ................................................................................................8
RESULTS ..........................................................................................................................10
Effort...............................................................................................................................10
Photo-id Effort from the Nevelskoy.............................................................................10
Photo-id Efffort from the Zodiac ................................................................................11
Group size and Distribution............................................................................................12
Individual Recognition and Sighting Patterns ................................................................12
Resighting, Site Fidelity and Association Patterns.........................................................13
Cow-Calf Pairs ...............................................................................................................13
Exchange between Piltun and Offshore feeding areas ..................................................14
Physical Condition..........................................................................................................15
Body weight ................................................................................................................15
Skin Sloughing ............................................................................................................16
DISCUSSION ....................................................................................................................16
LITERATURE CITED ......................................................................................................20
FIGURES
TABLES
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STUDY PARTICIPANTS AND AFFILIATIONS
Activity
Name
Affiliation
Field Photography and Videography
Photographer, Team
Leader
Yuri Mikhailovich Yakovlev,
Video Camera Operator
Vitaly Andreyevich Denisov
Marine Biology Institute of the
Far East Branch of the Russian
Academy of Sciences
Data Recorder
Aleksandr Vladimirovich Kalachev
Academy of Sciences
Zodiac Operator
Valery Ivanovich Fadeyev
Academy of Sciences
Academy of Sciences
Project Management and Training
Training: Familiarization
with protocols, analysis
procedures
Christina Tombach Wright
LGL Limited
Canada
Translation
Julia Yazvenko
Sergei Yazvenko
LGL Limited
Canada
Project Preparation
Sonya Meier
Steve Johnson
Sergei Yazvenko
LGL Limited
Canada
Russian Project
Management
Valeriy Vladimirov
VNIRO
Moscow, Russia
Olga Yuryevna Tyurneva
Yuri Mikhailovich Yakovlev
Arseny Yurevich Yakovlev
Photo-identification laboratory of
the Marine Biology Institute,
Vladivostok
Writing of the Report
Yuri Mikhailovich Yakovlev
Olga Yuryevna Tyurneva
Photo-identification laboratory of
the Marine Biology Institute,
Vladivostok
Editing, consulting
Sonya Meier
Sergei Yazvenko
Steve Johnson
LGL Limited
Canada
Data Analysis
Image processing,
Preparation of catalog
Writing of the Report
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ACKNOWLEDGMENTS
The scientific and vessel crew involved in the field season made this study possible.
Special thanks to the vessel’s captain for conducting the voyage and organizing safety
performance onboard, Boatswain Alexander Fyodorovich Kholodnyakov for providing
accident-free zodiac launches and recoveries, Nikolai Ivanovich Selin (Marine Biology
Institute, Vladivostok), for ensuring uninterrupted communication with the zodiac from
onboard the vessel, Mikhail Konstantinovich Maminov, marine observer (Pacific
Research Institute of Fisheries and Oceanography (TINRO), Vladivostok) for information
regarding whale distribution and transmitting information on whale movements in the
photo survey area to the zodiac, Aleksei Valerevich Vladimirov (All-Russian Scientific
and Research Institute of Fishery and Oceanography, Moscow) for providing several
photographs of whales taken in the offshore area from onboard the vessel during the
voyage in 2003.
A number of individuals from LGL Limited environmental research associates (Sidney,
British Columbia, Canada) provided support and training. We thank Sonya Meier, Sergei
Yazvenko and Steve Johnson for project preparation and management, Christina
Tombach Wright for providing technical training and support, Julia Yazvenko for
translation during training sessions and Peter Wainwright, Robin Tamasi, Tony
Mochizuki, Lucia Ferreira and Nathan Blakley for their technical help in storing and
organizing the digital photos.
Support and funding for this study was provided by Exxon Neftegas Limited and
Sakhalin Energy Investment Company. Valeriy Vladimirov of VNIRO was the Russian
manager for this study.
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LIST OF FIGURES
Figure 1. Locations of photo-identified gray whales along the northeast coast of Sakhalin
Island, 2003.
LIST OF TABLES
Table 1. Opportunistic photo-id of gray whales from the deck of the vessel Nevelskoy off
northeastern Sakhalin Island, 2003.
Table 2. Descriptive statistics from opportunistic gray whale photo-id from the deck of
the Nevelskoy off northeastern Sakhalin Island, 2003.
Table 3. Descriptive statistics from gray whale photo-id conducted from a zodiac in the
Piltun feeding area, northeast Sakhalin Island, 2003.
Offshore feeding area, northeast Sakhalin Island, 2003.
Table 5. Descriptive statistics from gray whale photo-id conducted from a zodiac off
Table 6. Number of aspects photographed for individual gray whales off the northeast
coast of northeast Sakhalin Island, 2003.
Table 7. Group size of gray whale sightings during photo-id along Sakhalin Island, 2003.
Table 8. Frequency of re-sightings of photo-identified gray whales in the Piltun and
Offshore feeding areas off the northeast coast of Sakhalin Island in 2002 and
2003.
Table 9. Number of re-sightings of photo-identified gray whales in the Piltun and
Offshore feeding areas off the northeast coast of Sakhalin Island, 2003.
Table 10. Feeding areas where individual gray whales were observed off northeastern
Sakhalin Island in 2002 and 2003.
Table 11. Sightings of individual whales, females with calves, body condition, and skin
condition, 2003.
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INTRODUCTION
There are currently two gray whale (Eschrichtius robustus) populations: eastern
(California-Chukotsk) and western (Korea-Okhotsk). Population estimates of eastern gray
whales peaked in 1999 at more than 26,000 (Rugh et al. 1999), however recent estimates
in 2001/2002 estimate the population is approximately 18,000 individuals (Rugh 2003).
In November 1991, by resolution of the US National Oceanic and Atmospheric
Administration, the eastern gray whale was removed from the endangered species list,
which had been its status since 1967.
In contrast, western gray whale numbers are not paralleling those of eastern gray whales
and the conservation status of the Korean-Okhotsk gray whale population is receiving
increased attention in recent years (Webster 2003). The Red Book of the Russian
Federation has listed the western gray whale as an endangered (Category I) species
(Perlov et al. 1996, Red Book of the Russian Federation 2001) and they are also
considered endangered by the United States government (USFWS 1997). Presently,
western gray whales are considered by the IUCN to be critically endangered (HiltonTaylor 2000, Weller & Brownell 2000). The IUCN Red List criteria used to support this
reclassification were as follows: (1) the population is geographically and genetically
distinct (LeDuc et al. 2002), and (2) the population plausibly contains less than 50
reproductive individuals (Hilton-Taylor 2000, Weller & Brownell 2000, Bradford 2003).
Much of the gray whale life cycle takes place in the coastal zones of densely populated
countries with intensive fishing and shipping. Western gray whales are vulnerable to
hazards at all three life stages: (1) during whale reproduction in the southern part of their
range, the location of which is presently unknown, (2) during prolonged northerlysoutherly migrations, the route which is presently unknown, and (3) in their known
feeding areas off the northeast coast of Sakhalin Island, Russia. Historically, the
distribution of gray whales in the Okhotsk Sea apparently included Sakhalin Bay (west of
the NW end of Sakhalin Island), Akademiia, and Tugurskii bays south of the Shantarskiy
Islands (in the far western Okhotsk Sea, west of the NW end of Sakhalin Island), the
coastal waters of northeast Sakhalin Island, in Shelikhova, Penzhinskaya and
Gizhiginskaya bays in the far northeast portion of the Okhotsk Sea, and in the waters west
of the Kamchatka Peninsula (Krupnik 1984, Yablokov and Bogoslovskaya 1984, Perlov
et al. 1996). The long-held belief that their wintering grounds were along the south coast
of the Korean Peninsula has not been recently substantiated (Rice 1998). Wintering
grounds are now believed to be located in the South China Sea, possibly along the coast
of Guangdong province and/or around Hainan Island (Rice 1998). However, specific
calving sites have never been observed. In addition to potential impacts on the whales
from increased vessel traffic connected with intensive fishing and commercial and
recreational navigation, the countries of East and Southeast Asia still have strong
traditions for consumption of whale meat (Lento et al. 1998, Wang 1998).
Photo-identification (hereafter referred to as “photo-id”) of marine mammals has proven
to be a useful tool for monitoring wild populations of animals while minimizing impact
on individuals. When incorporated into a long-term monitoring program conducted for
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several years, photo-id can be a valuable tool to answer many ecological questions about
populations of marine mammals. For small or closed populations, it has been used as an
effective method for estimating population size and change over time (Whitehead et al.
1997, Cerchio 1998, Stevick et al. 2001, Bradford 2003, Weller et al. 2003ab,
Calambokidis and Barlow 2004). For large whale populations, photo-id has been used to
establish long migration routes (Best et al. 1993, Darling et al. 1996, Craig and Herman
1997, Salden et al. 1999, Weller at al. 2002), feeding ranges and interannual changes in
whale distribution (Calambokidis et al. 2002). For these large whale species, photo-id can
also be used as a method to examine health indicators of individuals, as well as the
general health of groups and populations (Pettis et al. 2004). Photo-id methods have
proven extremely useful for gray whale studies (Darling 1984, Jones 1990, Weller et al.
1999, Calambokidis et al. 2002), as individuals are particularly well marked along their
sides, backs, and flukes.
Coastal areas are often acute conflict zones (Goldberg 1993) and since photo-id is often
the only method to available to record external health indicators of animals. In many
cases, photo-id of whales in regions with an elevated level or risk of anthropogenic
impact on the natural environment (coastal cities with industrial and domestic
wastewaters, oil development, intensive fishing and shipping, large-scale mariculture,
mass tourism) can help to resolve some conflicts. The important role of photo-id in
population monitoring and timely signaling of the appearance of negative phenomena
may sometimes prevent conflict or reduce the intensity of it.
OBJECTIVES
Sakhalin Energy Investment Company Limited (SEIC) and Exxon Neftegas Ltd. (ENL)
are currently developing oil and gas reserves in the Okhotsk Sea off the northeast coast of
Sakhalin Island, Russia and other companies are poised to begin developing reserves in
this area. Oil and gas development in proximity to western gray whale feeding areas
along the northeast coast of Sakhalin Island, especially during the spring to fall migration
and feeding period, could negatively impact western gray whales if not adequately
mitigated. The photo-id work is a key monitoring strategy to provide input to the need
and design of mitigation strategies and to monitor their effectiveness.
The technical objective of the work was to conduct photo-id to assess annual return rates
and patterns of site fidelity for known individuals, which will contribute to defining the
size, structure, and status of the population in general. Photo-id can be used to understand
various aspects of western gray whale ecology such as:
•
•
•
•
•
•
Number, status and habitat use of cow/calf pairs (calf production/survival);
Number of individual whales observed;
Population demographics and structure;
Number of re-sightings of individual whales (within and between feeding
seasons);
Patterns of individual whale movement;
Association patterns between individuals;
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•
•
•
•
Site-fidelity and interchange between feeding sites;
Individual Health Indicators;
Population Status; and
Individual foraging patterns and individual site-selection preferences.
BACKGROUND
Two primary gray whale feeding areas have been identified off Sakhalin Island. A
shallow (generally <20 m deep) feeding site is located along the coast adjacent to Piltun
Bay (Brownell and Chun 1977, Sobolevsky 2000; Weller et al. 2003b; Yazvenko et al.
2002; Blokhin et al. 2003, 2004, Yakovlev and Tyurneva 2003). Another deeper feeding
site is located ~30-40km offshore of Chayvo Bay in waters 35-60 m deep (Miyashita et
al. 2001, Maminov and Yakovlev 2002, Meier et al. 2002, Yazvenko et al. 2002, Blokhin
et al. 2003, 2004) (Fig. 1). However, whales are also observed ranging along the entire
northeast Sakhalin coast. Gray whales begin arriving off northeast Sakhalin Island in late
May, after sea ice has left the area, and some remain until early December, when sea ice
returns.
Photo-id of western gray whales is currently being conducted by two teams of
researchers. The US-Russian photo-id team has been working in the Piltun feeding area
during 1994-2003 (Würsig et al. 1999, 2000; Weller et al. 2000, 2001, 2003ab). The Far
East Branch of the Russian Academy of Sciences (IBM) started working in both the
Piltun and Offshore feeding areas during 2002 (Yakovlev and Tyurneva 2003) and 2003.
The US-Russian photo-id team deployed a zodiac from shore near the Piltun Bay
lighthouse and researchers focused their attentions on areas in the Piltun lagoon area
where the whales were found. According to data from these observations, a total of 131
whales had been identified as of late 2003 and the population is estimated to be less than
100 individuals (Weller et al. 2003a, D. Weller pers. comm., May 2004). It is important to
note that several of the animals reported by Weller et. al. may have died and the
population is thought to remain at approximately 100 animals. This team has documented
high levels of annual return and seasonal site-fidelity to the Piltun area for a majority of
all known whales (Weller et al. 2003ab). They have also reported that individuals are not
always present in the Piltun area, however, this may be explained in part by the recent
documentation of the Offshore feeding area in 2001.
Incidental sightings had been reported in this area in the past (Miyashita et al. 2001) and
it is very likely that the area has been significantly used by gray whales previous to 2001
but this use was not quantified before 2001 due to minimal survey effort in offshore
waters. Gray whale photo-id in the Offshore area in 2000 (Miyashita et al. 2001) and
2002 (Yakovlev and Tyurneva 2003) confirmed that some individuals observed in the
Offshore areas have also been observed in the Piltun feeding area and that there is
movement of whales between feeding areas within and between years. These results
suggest that the whales travel on their feeding grounds most likely in search of preferred
prey. The US-Russian photo-id team has reported that nine of ten whales photographed in
the Offshore area had been sighted in the Piltun feeding area at some point (D. Weller
pers. comm., May 2004).
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Major oil industry-funded studies examining western gray whale prey along the northeast
coast of Sakhalin Island began in 2001, continued in 2002 and 2003 (Fadeev 2003a,b;
Fadeev 2004), and are planned for 2004. The shallow depths (5-15 m) in the Piltun
feeding area along Piltun lagoon are characterized by an abundance of potential gray
whale food, such as swarming amphipods, isopods, clams, and worms. Predominant prey
species where whales were observed feeding in the Piltun area were amphipods, isopods
and bivalves and the biomass of benthos at sites where whales were observed feeding
averaged 234 g/m2 and amphipods accounted for 100.4 g/m2 of this average biomass
(Fadeev 2003a,b). Depths greater than 20 m along Piltun Bay are generally characterized
by high biomass of sand dollars, however cumaceans are also present in waters >20 m, a
species on which eastern gray whales have recently been observed feeding (S. Moore,
NMML pers. comm., March 2004). However, to date, western gray whales have not been
observed feeding on cumaceans. Studied for the very first time in 2002, the Offshore
feeding area was found to be a highly productive area dominated by tube-dwelling
benthic ampeliscid amphipods Ampelisca eschrichti, comparable in species composition
and richness to eastern gray whale feeding areas. This is the first time a highly productive
feeding ground with prevalence of Ampelisca eschrichti has been documented in the Sea
of Okhotsk. Ampelisca eschrichti live in dense clusters of tubes which extend 10-15 cm
above the bottom surface form a “forest” of tubes – or tube mats. Colonies of Ampelisca
eschrichti were found mixed with either bivalve mollusks or sea anemones. The average
total biomass of the feeding assemblage was 1180±157 g/m2 and amphipods accounted
for about half. The biomass of benthos at sites where whales were observed feeding
averaged 1228 g/m2 and amphipods accounted for approximately half of this biomass
(Fadeev 2003a,b). The density and biomass of Ampelisca colonies in some cases
exceeded the abundance in eastern gray whale ampeliscid feeding areas in the Bering Sea.
In both feeding areas, areas rich in food were located in smaller “patches”, and whales
were found to feed at the patches where a high biomass of prey was located..
Within and between season ‘shifts’ in the distribution of gray whales in both the Piltun
and Offshore feeding areas have been reported by many authors (Johnson 2002; Weller et
al. 2003b; Perlov et al. 2003; Blokhin et al. 2003, 2004) and are thought, in part, to be a
response to seasonal changes in the distribution and abundance of prey (Weller et al.
2003b; Fadeev 2003a,b, 2004). In addition, higher densities of whales are reported in
some parts of feeding areas compared to others. For example, a high density of whales
has been generally reported (1) along the southern portion of the Piltun feeding area near
the mouth of the lagoon (Weller et al. 2003b, Maminov 2004) where cows-calf pairs are
commonly observed (ENL/SEIC unpublished data) and (2) in the northern part of the
Piltun feeding area (Blokhin et al. 2003, 2004; Gailey et al. 2004, Maminov 2004).
‘Patchiness’ of gray whale prey may help explain aggregations and seasonal shifts in the
distribution of whales and movements of individual whales within and between the Piltun
and Offshore feeding areas (Maminov and Yakovlev 2002).
Seasonal fluctuations in blubber fat reserves in baleen whales is normal after winter
periods of fasting and during migration (Perryman and Lynn 2002) and cows can be
significantly thinner during years in which they are supporting a calf (Pettis et al. 2004,
Weller et al. 2003b). However, photo-id methods can be used to detect changes in body
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condition outside of the norm due to disease or starvation (Thompson and Hammond
1992, Pettis et al. 2004). Studies have shown a relationship between reproductive success
and body condition (Pettis et al. 2004) and photo-id allows one to look at the relationship
between calving success and body condition at individual and population levels. In 1999,
the US-Russian photo-id team noted that some of the whales they observed in the Piltun
feeding area were noticeably thin (Weller et al. 2000). They defined an abnormally thin
whale as having the following features:
•
subdermal protrusion of the scapulas with thoracic depressions where the
pectoral flippers connect with the body;
•
noticeable depressions around the blowholes and head; and
•
a pronounced ridge along the dorsal spine of the lumbar and caudal
vertebrae resulting in a bulge along the lateral flank.
During photo-id surveys in 1999 (Weller et al. 2000, Burdin et al. 2003), 23.2% of all
whales identified (16 of 69) were judged to possess one or more of the above criteria, and
during similar surveys in 2000 (Weller et al. 2001, Burdin et al. 2003) nearly half (30 of
58, 51.7%) of the gray whales identified were thin. In 2001, 72 individual whales were
identified and 19 adult gray whales out of the 66 adult whales (29% of adults) in the
western population were categorized as thin (Weller et al. 2003b, Burdin et al. 2003). The
proportion of skinny whales decreased in 2002 to 11.8% of observed individuals (9 of 76)
(Burdin et al. 2003) and in 2003, only 12.0% of individual whales (9 of 75) were
categorized as “skinny” (D. Weller pers. comm. May 2004). It is notable, however, that
some gray whales identified as thin in one year were observed to be recovering the next,
and some whales not previously reported to be thin were found to be thin the following
year (Weller et al. 2003b). During these years, many mothers with calves were
categorized as thin.
In 2002 (September - October) photo-id was conducted by IBM opportunistically in both
the Piltun and Offshore feeding areas when the mother vessel, Nevelskoy, encountered
gray whales and when sea conditions were favorable for photo-id work. Because a
number of western gray whale monitoring studies (prey sampling, vessel surveys,
acoustic monitoring) were also being conducted from this research vessel, photo-id
surveys were non-systematic and occurred when gray whales were encountered during
other vessel tasks. The discovery in September 2001 of a new primary offshore whale
feeding area (Maminov and Yakovlev 2002) offered IBM researchers the opportunity to
study whales in this area in detail for the first time and to determine if there were
movements of whales between these two areas. In 2002, photo-id of gray whales was
conducted along the entire northeast coast of Sakhalin Island, including both the Piltun
and Offshore feeding areas (see Yakovlev and Tyurneva 2003).
The US-Russian photo-id team and our photo-id group are continuing to monitor the
number of individuals in the population, determining the number of females with calves,
indirectly determining the physiological condition of gray whale individuals and tracking
the whales’ seasonal and daily movements in both the Piltun and Offshore feeding
regions.
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METHODS
Study Area
The study area included the entire northeast coast of Sakhalin Island including the Piltun
feeding area (N52°40’ to N53°30’) located along the coast adjacent to Piltun Bay and the
Offshore feeding area off Chayvo Bay (N51°50’ to N52°25’) at depths of 35-60 m.
Western gray whales were first documented using this Offshore area in significant
numbers during September 2001 (Maminov and Yakovlev 2002, Meier et al. 2002) and
were observed to utilize the area again during 2002 (Yakovlev and Tyurneva 2003,
Blokhin et al. 2003, Maminov 2003, Weller et al. pers. comm., May 2004) and 2003
(Blokhin et al. 2004, Maminov 2004).
The research vessel Nevelskoy was used as a convenient base platform for conducting
photo-id and other aspects of the marine mammal research and monitoring program,
including vessel-based marine mammal surveys, gray whale prey and acoustic research.
Therefore, the Nevelskoy traveled to locations along the northeast coast of Sakhalin Island
outside the known primary gray whale feeding areas where some gray whales were also
observed and photographed.
Field Photo-id
In 2003, opportunistic zodiac-based photo-id of gray whales was conducted on all days
when weather allowed safe conditions for use of the zodiac. During poor weather
conditions for photographing whales (high wind-driven waves, fog, torrential rain, high
seas and poor light), the work was halted due to its extremely low efficiency, the danger
of damaging the optical equipment, and potential threats to crew safety. In some of these
cases, photo-id was conducted from the mother vessel, the Nevelskoy. While the
Nevelskoy was performing prey sampling and/or acoustic surveys, no photo-id activities
were performed from the zodiac regardless of weather conditions due to safety concerns.
Photo-id was not conducted from the zodiac if the Nevelskoy was at anchor while
performing other expedition tasks and could not accompany the zodiac, in accordance
with safety protocols.
Visual marine mammal monitoring was conducted during daylight hours and observations
were continuous in all types of weather. Information about the location of gray whales
recorded from these continuous observations during other vessel research and monitoring
tasks allowed the photo-id team to travel directly to gray whale aggregations and reduce
search time. This was particularly true of the Offshore feeding area, where the distance
between groups of whales or individuals were quite considerable, and the whales'
movements were more unpredictable.
When the Nevelskoy came to within two kilometers of a group of gray whales in the
Offshore area, it slowed to a full stop. The bridge then informed the photo-id team
members about the whale sighting and after a safety briefing, the zodiac was launched
from the ship. In the Piltun area, the zodiacs were first launched and then used as the
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platform to search for whales. Photo-id missions began in conditions permitting safe
launching and operation of the zodiac as outlined in the safety regulations. The zodiac
used was a 4.8-m long, outboard-powered inflatable zodiac equipped with a digital depth
sounder and a Global Positioning System (GPS). The zodiac was also outfitted with all
safety equipment, as outlined in a zodiac mission safety plan. The research team consisted
of a boat driver, data recorder, digital video camera operator, and digital camera
photographer.
Upon initial sighting of a whale, the photo-id zodiac slowed to idle speed and
maneuvered to a vantage point approximately 100 m from the whale(s). From that
position, observations on whale location (as determined by the GPS), time, behavior, and
number of whales in the area, direction of their movement and the presence of killer
whales, passing vessels or airplanes and helicopters flying by in the vicinity were
recorded. Observations of mud feeding plumes were also recorded both nearby the whales
and when whales were not visible. Secondary indicators of whale feeding (such as
circling or diving birds in the vicinity or shoaling fish) were also recorded. If whale
foraging was observed (as confirmed by feeding plumes or assumed from movements and
behavior), the exact GPS position of the whale was recorded and communicated to the
Nevelskoy via VHF radio. Upon completion of the photo-id mission and only when the
zodiac and the whales had vacated the immediate area, the Nevelskoy would return to the
previously transmitted GPS coordinates to obtain benthic prey samples using a Van Veen
grab. All data was recorded on waterproof data sheets as used in 2002 and entered into a
notebook computer at the end of each photo-id mission.
The zodiac then moved within 50-100 m of the whale and the individual was
photographed. The photo frame and video counter number as related to particular whales
was recorded onto data sheets. Water depth (as determined by digital depth sounder),
location (as determined by GPS), water temperature (sea surface), salinity, and
environmental conditions were recorded for every mission and as they changed
throughout each photographic session. Photographs were taken with a Nikon D1X digital
camera equipped with a 300-mm fixed F.4 telephoto lens. The use of a high quality
digital camera allows rapid data acquisition and reduces the amount of time during the
post-season to process and archive images. The photographs were saved with a high
resolution and large format setting using JPEG expansion at maximum resolution and 0
compression and the RGB color model. The video camera “accompanied” and provided
additional supplementary information. Video footage was recorded on a Canon Optura 20
digital video camera in miniDV fine setting and maximum resolution. Video footage was
particularly important to document body condition characteristics (e.g. protruding
scapula, depressions behind the blowhole) that are difficult to capture in a still
photograph. Contact with a group of whales was maintained until all individuals
encountered were photographed or until a predetermined amount of time had passed.
After approximately one hour, we terminated the photographic session with a whale to
avoid excessive disturbance of the animal, regardless of the number of aspects
photographed. The zodiac was then motored away from the group. These procedures were
repeated each time additional whale groups were encountered and photographed.
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A sighting was defined as either a solitary individual, or two or more whales observed
close to one another (within about 10 body lengths of each other), and generally
coordinating their diving or direction of movement. Group size estimates were
determined from consensus among observers on the zodiac. A “calf” was defined as a
first year calf and were identified by their small body size (about one-third that of a
mature adult), and demonstrating close association with a particular adult whale
(Hamilton and Mayo, Wells and Scott 1990, Weller et al. 2003b).
Images of individual gray whales consist of various aspects of the body, including head,
back, dorsal flanks, and flukes. An attempt was made to photograph all aspects of each
whale. Whales were photographed sequentially from head to fluke on either the left and
right side, and the dorsal and ventral surfaces of their flukes. Priority was given to
photographing the right and left sides of each individual, as fluking tendencies vary with
individual behavior and foraging depth. Traditionally in gray whale photographic
identification, right and left sides then ventral flukes have been used for standard
matching procedures (Weller et al. 2002, Calambokidis et al. 2002). Since the likelihood
of recapture of an individual (via matching) increases as more information for that
individual is amassed into the catalogue, a fourth aspect - dorsal flukes, was added as
supplemental information to the matching process. Dorsal flukes of individual whales can
often be displayed even in shallow feeding areas, when deeper diving may not be feasible.
This technique of adding additional features in an effort to increase accuracy of the
matching process, especially during initial years of data collection and catalogue
development, has been employed for other marine mammal species with success
(Bannister 2000, Glockner-Ferrari and Ferrari 2000, McConkey 1999).
After the photo-id mission was completed, the zodiac returned to the Nevelskoy. All
digital images were downloaded from the camera’s memory card to a laptop computer,
backed up to a second external hard drive, and archived onto cds. After verifying that the
CD was readable, the data was erased from all of the memory cards in preparation for the
next photo-id mission. Information from the datasheets was entered into an Excel
database and backed up onto cds. All digital data information was simultaneously stored
at three digital locations at all times. All archive data cds were also duplicated with
duplicates stored in an offsite location whenever possible.
Photo and Video Analysis
The digital photographs were processed in Adobe Photoshop 7.0 and Adobe Illustrator 10
for subsequent identification and updating of the database. The best photographs for each
sighting were printed out on an Epson Photo Stylus 960 color printer onto high quality
photo paper and stored in the pre-catalogue binder. Backup copies of digital data were
made each day.
Standard photographic matching procedures for pattern-based matching of sides and
flukes were followed as described by the International Whaling Commission Special
Issue No. 12 (Hammond et al. 1990) This process has since been refined by others
working on gray and other large whales (Weller et al. 2003b, Calambokidis et al. 2002).
The following aspects of the whale’s body were selected to create the catalog (in order of
Page 8
priority): right (RS) and left (LS) sides of the body, ventral (VF), and dorsal (DF)
surfaces of the fluke. For each sighting, the photographs for that sighting and daily
mission (zodiac deployment from the mother ship) were reviewed and from all of the
photographs of the same animal, the best photos were selected to be placed into the
annual precatalog. Each new sighting was compared to previous sightings obtained in that
year (2003). If a match was made to an existing photo, it was grouped with other
photographs of that individual. After the photographs were matched down to individual
separated by aspect, they were compared to whales identified in 2002. If a new whale was
found, it was given a new identification number if a quality right or left side photo existed
for that individual. Identification numbers were not issued for fluke photos that could not
be matched to corresponding right or left sides. All images were then cross compared to
all of the ‘best’ photographs per sighting of the whales found in 2002 and 2003, in order
to determine the recurrence of encounters with the same whale and to insure that no
duplicate whales occurred in either the previous year’s catalogue or the current
precatalogue.
A confident match was not made unless the photograph was determined to be of good or
excellent quality (poor quality photographs were used for supplemental information only,
or digitally archived for potential future use). Side to fluke matches were considered to be
reliable when taken in sequential order and if the current photo contained portions of the
animal visible in the previous photo. Digital photography greatly assisted with side to
fluke matching because of this process. Confident left to right side matches were
established by a number of criteria: (1) the whale was photographed as a solitary
individual, (2) two sequences were compared with flukes in common for a single
sighting, and (3) as a final check to compare matches and assist with right to left matches,
whale knuckle height, spacing and ratios were compared (see Calambokidis et al. 1999).
This process had to occur three times and be verified by two to three independent
matchers before a right to left match was given confidence of 90% or higher and
promoted from the pre-catalogue to the final annual catalogue. All whale sighting
matches as well as right-left matches and side-fluke matches were verified by two to three
independent matching specialists. Whale body pigmentation was the primary feature used
to distinguish individuals, with scars and body markings supplementing the matching
process. If the annual pre-catalogue matching seemed in order, the whales would be given
permanent identification numbers and promoted to the final catalogue. Once the final
annual catalogue is completed, any discrepancies between the current annual catalogue
and the current catalogue to date will be corrected. Any missing aspects for known
whales will be incorporated into the current catalogue and new whales will be added.
This process is still ongoing and the merging of the two annual catalogues (2002 and
2003) into one current catalogue has not been completed to date. The available
photographs of different aspects of an individual animal were supplemented by
photographs of that whale which showed a clear distinguishing mark and could serve as
good additional material for field observations. Special attention was given to identifying
whales with various deviations from the physiological norm including: (1) thin whales
subdivided into four classes of body condition and (2) whales with visible skin sloughing.
Analysis of video footage was not completed upon the writing of this report.
Page 9
RESULTS
Effort
Photography and videography of whales were done with varying effort from 7 August to
19 September 2003. The efficiency of the photo-id team’s work depended heavily on the
season’s weather conditions. In particular, there were many days of fog during the first
half of the expedition. The distribution of time spent by the expedition on the Nevelskoy
in 2003 was as follows: out of the 69 days of the voyage, 40 were working days; 16 were
spent on trips to the work sites and for refueling; and 13 were stormy. The productivity of
the survey days depended heavily on the time spent searching for whales. This was
especially true of work in the Offshore feeding area.
To calculate effort, we combined the data on photo-id conducted from the zodiac and
from the deck of the Nevelskoy. The total number of days during which some time was
spent on photographing whales was 23 days, including two days when a photographs
were taken from the deck of the Nevelskoy and from the zodiac on the same day.
Characteristics that can be used to assess the efforts involved in photo-id of gray whales
off Sakhalin Island in 2003 are reported in Tables 1-5.
Photo-id zodiac-based missions in the Piltun and Offshore feeding areas were similar
(Table 2). The number of whale sightings from the Nevelskoy approximately
corresponded to the number of whale sightings in the Piltun area (80) and in the Offshore
area (66) with the use of the zodiac (Tables 3 and 4). However, the number of highly
informative photographs with all four photo-id aspects was significantly less than for the
surveys from the zodiac. Therefore, photographs taken from the Nevelskoy may provide
good supplementary data in addition to the basic data obtained by photographing whales
from the zodiac. Processing of photos in Photoshoр7 allowed us to improve the image
quality of about 70% of the photographs to an acceptable quality, by adjusting levels of
brightness, and cropping images. They provide satisfactory supplementary material on the
whales’ daily and seasonal movements in the feeding areas.
The higher photo-id effort and number of photo-id whale encounters in 2003 compared to
2002 is due to: (1) supplemental photos taken from the deck of the Nevelskoy in 2003, (2)
less expedition time devoted to benthic sampling in control areas in 2003 where whales
are unlikely to be encountered, (3) more time devoted to benthic prey sampling where
whales are observed feeding, resulting in more time searching for and photographing
feeding whales, and (4) expertise gained from the 2002 increased efficiency in 2003. A
reprocessing of 2002 photographs is necessary now that the 2003 catalogue is available.
Additional photographs of solitary flukes and photos containing body fragments other
than standard placement of the dorsal hump central to the photograph, may be matched to
previously missing whale aspects thereby increasing whale sighting numbers and
decreasing recapture error.
Photo-id Effort from the Nevelskoy
Opportunistic photo-id was conducted from the deck of the Nevelskoy on eight days
(Table 1). From the deck of the Nevelskoy, 445 photographs of whales were taken in the
Page 10
Piltun feeding area and 397 in the Offshore feeding area (Table 2). The average number
of frames taken per whale from the deck of the vessel was 12.4 in the Piltun area and 12.8
in the Offshore area.
Photo-id Effort from the Zodiac
During the previous expedition in 2002, 13 days were spent conducting photo-id work, or
22.8% of the total expedition time (Yakovlev and Tyurneva 2003). During the 2002
voyage, from 13 photographic survey days the total photo-id effort (not including travel
time to and from the vessel to the first whale position) was 44 hours and 14 minutes
(Yakovlev and Tyurneva 2003). According to the data from 2002 field observations, 93
whale sightings were recorded from the zodiac.
In 2003, photo-id work was conducted from the zodiac on 17 days, which was 24.6% of
the total expedition time. The total time spent directly on the photo-id was 42.6 hours –
17.2 hours for the Piltun area (7 days) and 25.4 hours for the Offshore area (10 days).
According to only partially analyzed data, 3,034 photographs of whales were taken from
the zodiac during the 2003 expedition in the Piltun area and 3,137 photos in the Offshore
area (Table 5). During photo-id missions in 2003, 86 sightings totaling 146 unidentified
whales (including repeat encounters with individuals) were encountered from the zodiac.
An average of 39.7 frames were taken per whale that was encountered in the Piltun area
and 47.5 in the Offshore area (Tables 2 and 5).
In the Piltun area, whales were photographed on 7 days in 2003 (4 days in 2002),
consisting of 14 missions (8 missions in 2002). During this time, 80 whales (unidentified)
were photographed (possibly including repeat encounters with some individual whales).
The average number of whales encountered in this area per day was 11.4. In 2002, there
were 21 such encounters, and the average number of whales per day was 5.25.
In the Offshore area, whales were photographed on 10 days from the zodiac (9 days in
2002), consisting of 21 missions (17 missions in 2002). The average number of whales
photographed in this area per survey day was 6.6. In 2002, 8.0 whales were photographed
per day.
Taking photos of all four aspects proved to be extremely important not only for creating
the precatalog of whales that we photographed for the first time in 2003, but also for
updating photographs of whales with aspects that had not been completely photographed
in 2002. In 2003, 39 individual whales were completely photographed (all four aspects
(Table 6). Eleven whales were photographed on three sides; 23 whales were
photographed for two aspects; and eight whales were only photographed for one aspect.
Calves rarely showed their flukes and therefore, only sides were photographed. In 2002,
all four aspects were documented for 17 individuals; three aspects were photographed for
3 individuals; two aspects were photographed for 9 individuals; and only one aspect was
photographed for 17 individuals (Yakovlev and Tyurneva 2003). Comparison of the 2002
and 2003 seasons indicate that the more aspects per whales were documented in 2003
than in 2002, most likely as a result of increased experience on part of the zodiac driver
and the photographer and the use of the digital camera, as well as partially do the unequal
Page 11
effort between the Offshore and Piltun regions and the behavioral differences of foraging
whales in deeper waters. Whales in the Offshore area, were not cow/calf pairs, and were
located in deeper waters and therefore showed flukes more regularly, with deeper and
regular diving patterns than whales identified inshore in Piltun.
Group size and Distribution
Mean group size for 122 groups observed in 2003 was 2.03 with a range of 1-5 whales
per group. Solitary gray whales accounted for 48.3% of all whales that were observed off
the northeast coast of Sakhalin (this figure may include repeat encounters and errors in
determining the true number of them, due to relatively brief observations). Groups of two
individuals accounted for 31.6%; groups of three - 15%; four - 3.3%; and groups of five
whales - 1.6% (Table 7).
There were differences in group size between the Offshore and Piltun feeding areas. The
percentage of solitary whales in the Offshore area was 56.89%, while in the Piltun area it
was 40.32%. Groups of two whales accounted for 22.41% in the offshore area and
40.32% in the Piltun area. Groups of three whales accounted to 17.24 % and 12.9%, in
the Offshore and Piltun areas, respectively. The percentage of whales in groups of four
was the same in the two areas. Two sightings of five whales were discovered only in the
Piltun area (see Table 7).
The average depth in the Piltun area where whales were photographed was 14.1 m (range
6 - 30.4 m), while in the Offshore area it was 52.3 m (range 44.1 – 64.2m). Water
temperatures in both areas were similar (see Table 5). In the Piltun feeding area, most
sightings were within 5 km of shore (range 0.2 – 7.5 km). In the Offshore area, whales
ranged between 12-50 km from shore and whales were observed further east than in
previous years (see Maminov 2004). This may in part be explained by minimal survey
effort over the 50 m contour line in 2001 and 2002 compared to 2003.
Individual Recognition and Sighting Patterns
From 7 August to 19 September 2003 (23 working photo-id days), there were 214
encounters with gray whales. Analysis resulted in the documentation of 154 sightings of
81 individual whales (Table 8). In the Piltun and Offshore feeding areas, 50 and 35
individual whales were observed, respectively (Table 9). Four individual whales were
observed in both the Piltun and Offshore feeding areas. In total, in 2002 and 2003, 96
individual whales have been identified.
To date, 17 individual whales have been identified from the images collected from photoid from the Nevelskoy, which have not yet been completely processed and six whales
were new in 2003 (id numbers RGW049, RGW067, RGW072, RGW075, RGW076 and
RGW086).
Page 12
Resighting, Site Fidelity and Association Patterns
It is interesting to track the frequency of encountering identified individual whales over
time within and between the 2002 and 2003 seasons (Table 8 and 10). In 2002, there were
66 sightings consisting of 47 photo-identified whales. In 2003, there were 154 such
sightings of 81 individual whales. The average number of sightings per identified whale
was 1.40 in the 2002 and 1.90 in 2003 (Tables 8 and 9). The monthly presence of absence
of whales in 2002 and 2003 in shown in Table 10.
The frequency of encountering identified whales during the whole photo survey period in
2003 was as follows (see Table 8): 36 whales were encountered once; 23 whales, twice;
16, three times; and 6 whales were encountered four times. In 2002, 29 whales were
encountered once; 14, twice; and 3 whales were encountered three times.
In 2003, we were able to track the route of whale RGW002 for one day on 5 September in
the Offshore feeding area from 10:50 AM until 5:13 PM. Over the course of a day, this
whale traveled ~20 km over an area ~50km2. The observation of this animal serves as a
good illustration supporting Bogoslovskaya’s statement (1966) about the temporary
nature of groups of gray whales. On 27 August 2003, whale RGW002 was feeding
together with whale RGW012. The following day, whale RGW002 was feeding alongside
whale RGW088. On the morning of 5 September, RGW002 was observed with whales
RGW013 and RGW035, and RGW020 but by the afternoon, was observed alone. On 8
September, RGW002 was observed again with whale RGW035, and was joined by whale
RGW040, which had been observed in the Piltun area 10 days earlier. Whale RGW020,
which had been swimming together with whale RGW002 on 5 September was observed
alone nearby.
As we can see from the examples given, repeat encounters with whales and photographic
recording of them over the course of a day, as well as encounters with the same whales
over the course of a season, provide very important data on how fast the whales move in
their feeding areas and the dynamics of their visits to these areas.
Cow-Calf Pairs
In addition to monitoring the size of this population, it is very important to continue to
monitor the number of females with calves and indirectly document health status through
indicators such as body weight and skin condition. Photo-id conducted by the US/Russian
photo-id team has indicated that fewer than 50 reproductive adult individuals have been
documented along the northeast coast of Sakhalin Island, 14 of which are reproductive
females (D. Weller pers. comm., May 2004).
In 2003, we identified ten cow-calf pairs (Table 11) (two more calves still need to be
precisely identified from the video data). Cow-calf pairs were only observed in the Piltun
area. On 25 August, a group of three calves with one adult female (RGW041) was
observed. On 18 September, a group of four calves without any adults present was
observed. On 19 September, the female RGW041 was encountered alone without a calf.
This agrees with Weller et al. (2000) that the calves make the transition to swimming on
their own in July-September. According to Bogoslovskaya's data (1996) for the gray
Page 13
whales in waters of the Chukchi Peninsula, age differentiation of the groups begins in
July-August, when the calves leave their mothers and gather together in the shallowest
waters rich in food.
Exchange between Piltun and Offshore feeding areas
The discovery of a primary feeding area offshore of Chayvo Bay in 2001 (Maminov and
Yakovlev 2002) gave us the opportunity to determine the nature of the animals'
movements between the Piltun area and the newly documented Offshore area.
The frequency of encounters with identified individual whales during the entire survey
period is important in determining how much exchange of whales there is between these
two areas. In 2003, 85 sightings of 51 identified individuals were observed in the Piltun
area and 69 sightings of 34 identified individuals in the Offshore area (see Table 9) and
only four individual whales were observed in both the Piltun and the Offshore areas (see
Tables 9 and 10).
One whale (RGW040) was observed in the Piltun area on 24-25 August and was then
observed in the Offshore area on 8 September. Another whale (RGW045) was observed
in the Piltun area on 23 and 25 August and in the Offshore area on 5 and 8 September. A
third individual (RGW062) was observed in the Piltun area on 3-4 September and in the
Offshore area on 13 September. It is interesting that on 15 August whale RGW037 was
encountered in the Piltun area, was observed again on 7 September in the Offshore area,
and 12 days later was once again observed in the Piltun area. According to our data from
2002, only one whale, RGW026, was documented in both the Piltun and Offshore feeding
areas in the same season.
Of the 32 whales that were individually recognized during both 2002 and 2003, 10
individuals were observed in both areas. The majority of these individuals were recorded
in 2002 in the Offshore area and in 2003 in the Piltun area. The whales observed in the
Offshore area in 2002 were primarily females without calves and were observed with
calves in the Piltun area in 2003. Movements between feeding areas and habitat use of
females with calves will be more fully understood and more fully substantiated
statistically only when data is accumulated after additional surveys in 2004.
It is important to note that our team spent limited time in the Piltun feeding area for parts
of two feeding seasons in 2002 and 2003 (see Table 5). As additional data are collected, it
is likely that a significantly higher percentage of the whales observed in the Offshore area
will have been sighted at some time in the Piltun area and vice versa. D. Weller has
reported that up to 2003, 9 of 10 whales photographed in the Offshore area had been
sighted in the Piltun feeding area at an earlier time (D. Weller pers. comm., May 2004).
Page 14
Physical Condition
Body weight
In 2003, during data processing, several whales appeared visibly thinner than expected
after winter. A hierarchal system of categorizing the levels of emaciation of the whales
was developed based upon the original methods outlined by Weller et al. (2001) from
slightly thin whales of the Class 1 to Class 3 (Table 11). The video data, which are the
most acceptable data format for making this determination, have not yet been completely
processed, but has only been reviewed to date to supplement the photo-id matching and
analysis process. Photographic examples of each of the classes and a “Body Condition
Key” is under development and will be available for 2004. A whale was defined to be
undernourished if one or more of the four following criteria were observed (adapted from
Weller et al. 2003a):
•
•
•
•
an obvious subdermal protrusion of the scapulas from the body with
associated thoracic depressions at the posterior and anterior insertion points
of the pectoral flipper
the presence of noticeable depressions or concavities around the blowholes
and head with a post-cranial ‘hump’ along the dorsal surface
a pronounced ridge along the neural/dorsal spine of the lumbar and caudal
vertebrae resulting in the appearance of a bell-shaped body and ‘bulge’ along
the lateral flank
presence or protruding ribs and vertebrae along the dorsal surface and/or
lateral flanks or ribcage
If any one or more of the above criteria were observed and noted in photographs
or video data, the subject animal was categorized based upon body condition for that
sighting. The final categorization given to a subject animal is the highest Class number
associated with that animal for any given field season. The body condition classes are
defined as follows:
Class 0:
Class I:
Class II:
Class III:
whale shows no cases of any of the four above criteria
whale shows a mild case of any one of the four criteria
whale shows a moderate case of any of the four criteria
whale shows an extreme case of any of the four criteria
The subjective terminology of mild, moderate, and extreme were agreed upon as a group
by the photo-id team and advisors, with specific photographic or videographic examples
for use as a “key”. Photographic illustrations of each of these cases will be prepared
(when photos are available) for subsequent reports. In all, 21 undernourished whales were
observed.
The fewest thin whales were found in the Offshore feeding area. Out of 11 whales, six
were categorized as Class I, four were categorized as Class II, and one was Class III. In
the Piltun area, 11 whales observed with one or more of the defined criteria were
Page 15
observed. One was classified as Class I, eight of them were defined as Class II; and two
Class III (Tables 10 and 11). One whale classified as Class I was observed in both the
Piltun and Offshore areas in 2003. It is noteworthy that the most pronounced emaciation
was for females with calves. Of the 11 whales observed in the Piltun area with signs of
the above criteria, eight were females with calves. The sex of the other three whales is
unknown.
When we calculated the percentage of thin whales in relation to the number of animals
observed, Class I was disregarded, since it is insignificant in its manifestation. So, the
percentage of thin whales (Class II or greater) was 18.52% of the total number of whales
assessed in 2003 (15 out of 81). Class I whales were usually considered either to be in
recovery (if the individual was classified as undernourished in previous years), poor
photographic examples, or to be within the normal range variation in body weight for
migratory and seasonally foraging populations. No calves were observed possessing any
of the criteria defining a thin whale and were categorized as Class 0.
Skin Sloughing
During processing of the photo-id data from 2003, cases of skin disorders were observed
on nine whales, which were not observed in 2002 (see Table 11). Except for one animal,
all of the whales with observed skin problems were observed in the Piltun area with
various degrees of epidermal sloughing. Whales RGW029 and RGW059 were
encountered over the course of several days. In these cases, skin sloughing appeared to
begin from the backbone. In one day, from 24 to 25 August, skin sloughing progressed
rapidly on whale RGW029. A few days later, the whale was observed with no sloughing
skin. This same pattern was observed with whale RGW059. This molting or shedding
process seemed to progress in stages starting at the backbone (m1) progressing down the
body toward the ventral surface or belly (m2) until all dead or damaged skin was
sloughed and the whale was observed with no evidence of sloughing (m3). Four whales
with observed skin sloughing were categorized as “skinny” (≥ Class II) and were cows
with calves.
DISCUSSION
Preliminary results of photo-id effort conducted in 2002 and 2003 along the northeast
coast of Sakhalin Island in the primary gray whale feeding areas identified a total of 96
individual gray whales. Combination of the two years of work into one current catalogue,
and establishing a protocol for least population count such as only counting right or left
sides of individuals (Darling 1984, Weller et al. 2001, Weller et al. 2003b) will provide
better confidence in least-count estimates for population size. Naturally, the number of
encounters with whales that have already been photo-identified will rise with each new
season, as will the confidence and ease of the entire matching process. Newly obtained
data on the same whales are very valuable for determining their return to feeding places,
distribution, physiological condition and recording changes in their photo-id
characteristics during the year.
Photo-id analysis from 2002 and 2003 showed that gray whales move within and between
the Piltun and Offshore areas both within and between years. As was shown above,
Page 16
information about the whales’ movement between areas over the course of a single season
is only provided by repeat encounters with individually recognized whales in the same
season. A single encounter with a gray whale in one area in a season and a subsequent
photo-recording of it (even just one) in the other area in the next year also indicates
exchange between the feeding areas (see Table 10). Therefore, the absence of individuals
in the Piltun feeding areas as reported by Weller et al. (2003b) may be a result of
individual whales spending more time in the Offshore feeding area. The absence of
whales in the Piltun and Offshore feeding areas may also be explained by whales ranging
outside of these primary feeding areas. Recent observations of feeding gray whales south
of Piltun Bay near Lunsky Bay (SEIC unpublished data) and recognition of individual
whales at other locations in the Sea of Okhotsk (Weller et al. 2002) suggest that the
annual range of individual gray whales requires further study.
Seasonal variability in the distribution of cetaceans has been extensively reported and is
thought to be a response to seasonal habitat fluctuations and movements of prey (Payne et
al. 1986, Piatt et al. 1989, Payne et al. 1990, Kenney et al. 1995, Weinrich et al.1997,
Wilson et al. 1997, Forney and Barlow 1998, Karczmarski et al.1999). Eastern gray
whales feeding along the west coast of Vancouver Island, Canada, rotate feeding sites and
prey types within and between summer feeding seasons as a function of the distribution
and abundance of their prey (Bass 2000; Dunham and Duffus 2001, 2002; Meier 2003,
Kopach 2004). The distribution of feeding eastern gray whales along the west coast of
North America is variable within and between years with whales utilizing areas from
northern California to southeast Alaska from spring to fall involving significant
interchange of individuals between areas with variable use of habitat within and between
years (see Calambokidas et al. 2002). Recent research has indicated that eastern gray
whales are dynamic and selective foragers that can use various types of prey and foraging
tactics rapidly to take advantage of short-term availability of energy and are not
exclusively benthic foragers (Dunham and Duffus 2001, 2002; Moore et al. 2003).
Eastern gray whales are multi-scale animals that can show site-fidelity at a regional scale
(e.g. northeast Sakhalin Island) but range over a larger area to use smaller sites or “nodes”
within the region as a function of the distribution and abundance of prey over time. In
addition to responding to the distribution and abundance of prey, there is some evidence
that eastern gray whales and other apex predators can significantly influence the
distribution and abundance of their prey through foraging (Bowen 1997, Meier 2003).
These “top-down” effects can alter a prey community to the extent that whales will
abandon it for months or years while it recovers to a richness than can be utilized again,
influencing the seasonal distribution of the whales. Although western gray whales are
genetically isolated from eastern gray whales, it is likely that the manner in which eastern
and western gray whales make foraging decisions in response to the distribution and
abundance of prey in different ecological contexts is similar.
Without a doubt, the Offshore region is a more difficult area in which to conduct photoid. One of the possible reasons for this is the greater water depths in this area, therefore
whales are diving longer and the locations where they surface are more unpredictable and
farther from the zodiac than in the Piltun area. The area is not sheltered by proximity to
land or shallows, and therefore is subject to more pronounced wind and wave effects,
conditions that make photo-id difficult. In addition, due to the larger size of the Offshore
Page 17
area, it is more difficult to find aggregations of whales or solitary individuals from the
mother ship Nevelskoy. The large size of this area means that the observers may be
unaware that the whales have moved into an area that has already been surveyed, and this
time was wasted trying to find whales.
The continued observation of abnormally undernourished whales remains unexplained
(also see Weller et al. 2003b). The causes of emaciation in both North Pacific populations
of gray whales are not clear, but several lines of evidence suggest that over-exploitation
of the available food supply and/or a possible large scale climatic/oceanographic regime
shift affecting productivity in the North Pacific region have been at least partially
responsible. As the population of eastern gray whales increases to levels estimated to be
above those before the period of American whaling intraspecific competition pressures in
the subarctic feeding grounds may be increasing (LeBoeuf et al. 2000, Moore et al. 2001,
2003). Other authors have suggested that changes in the extent and concentration of sea
ice in the Arctic Ocean due to global warming over the past twenty to thirty years may
alter seasonal distributions, geographic ranges, patterns of migration, nutritional status, or
reproductive status (Tynan and DeMaster 1997, Perryman et al. 2002) potentially
resulting in increased use of subarctic areas. Grebmeier and Barry (1991) suggest that due
to global warming, primary production in surface waters may be depressed resulting in a
reduced availability of benthic prey. LeBoeuf et al. (2000) suggested that reduced
availability of prey caused by a decline in productivity in the North Pacific may be
limiting gray whale feeding in subartic areas. It is conceivable that these large-scale
climatic/oceanographic events may have affected the entire North Pacific region and thus
may have had simultaneous and similar impacts on both the western and the eastern gray
whale populations (see Brownell and Weller 2001). However, recent gray whale prey
studies have identified the Piltun area, and particularly the Offshore feeding area, as very
rich prey sources (Fadeev 2003a,b, 2004) and it unlikely that food is limiting, however
this requires further study. It is also conceivable that some other factor(s), such as disease
or anthropogenic impacts during winter, migration, and/or the summer feeding period,
may have simultaneously and similarly affected one or both gray whale populations.
Interestingly, some whales that showed signs of emaciation in 2002 did not show such
signs this year and Weller et al. (2003b) has reported similar seasonal recovery.
In addition to unexplained thin individual whales, skin sloughing was observed in some
animals in 2003. This phenomenon remains unexplained, but may be a result of several
factors including diseases caused by bacteria, viruses, fungi (Gaydos et al. 2004), internal
and external parasites, pollution, or excessive exposure to freshwater. Cetacean
poxviruses can cause skin lesion ‘tatoos’ or ‘rings’ (Van Bressem et al. 1999) and it has
been suggested that poxvirus infection could cause neonatal and calf mortality in affected
individuals (Van Bressem et al. 1999). Skin lesions in bottlenose dolphins caused by
poxvirus were observed to become raised and blanched, then disappeared with sloughing
skin (Smith et al. 1983). Skin lesions have also been observed in dolphins living in cold,
low saline waters (Thompson 1999). In 1987 and 1988, several hundred bottlenose
dolphins washed up dead along the US coast with lesions and severe skin sloughing and
an investigation by NOAA determined that these dolphins had been poisoned by a
naturally occurring red tide toxin. Health effects from red tide toxins have also been
reported in other marine mammals (Dhermain et al. 2002, Durbin et al. 2002). Organic
Page 18
pollutants have been implicated in the high incidence of tumours and skin lesions in
marine mammals by disrupting hormones in the body (Béland et al. 1992). Similar skin
peeling has been reported in blue whales (Sears et al. 2000) and right whales (Pettis et al.
2004), but is previously unreported in the eastern or western gray whale populations. It is
important to note that only skin sloughing was observed and skin lesions were not
observed.
Our preliminary observations suggest that this skin sloughing is very reminiscent of
natural annual molting. The white whale (beluga) is the only whale species that molts
annually (Boily 1995). Beluga whales go through an annual molting, which takes place
when the temperature and salinity of the water change. The examples of skin sloughing
that we documented showed that the skin recovers relatively quickly after sloughing, and
no subsequent pathological consequences are observed on the surface of the whale’s skin.
This phenomenon requires further study to understand the duration and meaning of skin
sloughing events. It is especially important to document whale skin sloughing in 2004 in
whales that were found with skin sloughing in 2003. It is also important to note that
known animals in 2002 that were observed sloughing in 2003 had not shown any peeling
of skin in the 2002 photographs. Further photography of the whales' skin, as well as direct
skin samples from the affected areas for histological study and analysis could be collected
to determine the presence of pathogenic viruses, microbes or fungi.
Page 19
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Unpublished final Report by Texas A&M University, College Station, TX and
Kamchatka Institute of Ecology and Nature Management, Russian Academy of
Sciences, Kamchatka, Russia, for Sakhalin Energy Investment Company Limited
and Exxon Neftegaz Limited, Yuzhno-Sakhalinsk, Russia. 101 p. [available on the
Sakhalin Energy Investment Company website http://www.sakhalinenergy.com/
environment/ env_whales.asp].
Würsig, B.G., D.W. Weller, A.M. Burdin, S.H. Reeve, A.L. Bradford, and S.A. Blokhin.
2000. Gray whales summering off Sakhalin Island, Far East Russia: JulySeptember 1998. A joint U.S.-Russian scientific investigation. Unpublished
contract report by Texas A&M University, College Station, TX, and Kamchatka
Institute of Ecology and Nature Management, Russian Academy of Sciences,
Kamchatka, Russia, for Sakhalin Energy Investment Company Limited and Exxon
Neftegas Limited, Yuzhno-Sakhalinsk, Russia. 139 p. [available on the Sakhalin
Energy Investment Company website http://www.sakhalinenergy.com/
Yablokov,A.V., and L.S. Bogoslovskaya. 1984. A review of Russian research on the
biology and commercial whaling of the gray whale. Pages 465-485 In: M.L.
Jones, S.L. Swartz, and S. Leatherwood (eds.) The gray whale Eschrichtius
robustus, Academic Press, Orlando, FL.
Yakovlev, Y. M. and O.Y. Tyurneva. 2003. Photo-id of the Korean-Okhotsk gray whale
(Eschrichtius robustus) population in 2002. Unpublished final report for Exxon
Neftegas Limited, Yuzhno-Sakhalinsk, Russia and Sakhalin Energy Investment
Page 28
Company Limited, Yuzhno-Sakhalinsk, Russia, 27p. [available on the Sakhalin
Energy
Investment
Company
website
Yazvenko, S., T. MacDonald, S. K. Meier, S. Blokhin, S.R. Johnson, V. Vladimirov, S.
Lagerev, M. Maminov, E. Razlivalov, M. Newcomer, R. Nielson and V.C. Hawkes.
2002. Aerial marine mammal monitoring during the 2001 3-D seismic survey of the
Odoptu block, northeast Sakhalin Island, Okhotsk Sea, Russia. Contract report by
LGL Limited environmental research associates, Sidney, Canada for Exxon
Neftegas Limited, Yuzhno-Sakhalinsk, Russia. 111 p.
Page 29
FIGURES
Page 30
Figure 1. Locations of photo-identified gray whales along the northeast coast of Sakhalin
Island, 2003.
Page 31
TABLES
Page 32
Table 1. Opportunistic photo-id of gray whales from the deck of the vessel Nevelskoy off
Date
8/9/2003
8/13/2003
8/14/2003
8/15/2003
Area
Piltun
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
8/18/2003
8/23/2003
8/25/2003
9/8/2003
8
days
Offshore
x
x
x
x
x
x
x
x
x
x
x
x
17
sightings
x
x
x
x
x
x
x
x
x
19
sightings
Sighting
Number Number of
number of whales frames
1
1
3
1
2
6
2
3
7
3
2
3
4
1
7
5
2
9
6
1
7
1
1
9
1
2
8
2
2
13
3
2
3
4
1
14
5
1
18
6
2
11
7
5
41
1
2
30
2
1
36
3
2
27
4
1
2
5
1
4
6
3
8
7
1
2
8
1
6
9
1
3
1
3
87
2
3
94
1
3
114
1
1
6
2
1
5
3
3
26
4
2
57
5
2
35
6
3
31
7
3
69
8
1
26
9
1
15
36
67
842
sightings
whales
frames
Sighting duration
min.
5
4
4
4
8
6
5
6
5
9
4
6
5
5
9
4
9
16
4
3
15
1
4
2
19
21
25
2
6
3
11
6
3
18
4
2
263
min.
Page 33
Table 2. Descriptive statistics from opportunistic gray whale photo-id from the deck of
the Nevelskoy off northeastern Sakhalin Island, 2003.
No.
1
3
4
6
7
9
12
13
15
16
Parameters
Number of survey days
Number of sightings
Total number of whales sighted (field data)
Average number of whales per survey day
Average number of whales per sighting
Total duration of sightings, min.
Number of frames
Average number of frames per survey day
Average number of frames per sighting
Average number of frames per whale
Piltun
Area
5.0
17.0
36.0
7.2
2.1
144.0
445.0
89.0
26.2
12.4
Offshore
Area
3.0
19.0
31.0
10.3
1.6
119.0
397.0
132.3
20.9
12.8
Page 34
Total for
Both Areas
8.0
36.0
67.0
8.4
1.9
263.0
842.0
105.3
23.4
12.6
Piltun feeding area, northeast Sakhalin Island, 2003.
Date
8/24/2003
8/25/2003
9/2/2003
9/3/2003
9/4/2003
9/18/2003
9/19/2003
7
days
Mission
number
1
2
3
3
3
3
1
1
1
1
1
1
1
1
2
3
3
3
3
3
1
1
1
1
2
2
2
2
2
1
1
1
1
1
2
2
2
2
3
3
3
3
1
1
1
1
14
missions
Sighting
number
1
1
1
2
3
4
1
2
3
4
5
6
7
8
0
1
2
3
4
5
1
2
1
2
1
2
3
4
5
1
2
3
4
0
1
2
3
4
1
2
3
4
1
2
3
4
46
sightings
Number
of whales
1
2
1
2
2
2
2
2
2
1
2
4
2
3
0
1
3
1
2
1
1
1
4
2
5
1
2
2
1
2
2
3
2
0
1
1
1
1
2
1
3
2
1
1
1
1
80
whales
Duration, (min.)
Mission Sighting
Trip
72
23
49
55
33
22
327
53
98
59
68
49
180
10
91
10
5
8
13
23
8
12
152
0
152
94
6
41
19
2
20
6
113
28
33
52
195
67
97
31
127
25
60
12
23
2
5
162
11
73
37
26
15
80
0
80
110
18
33
29
5
25
135
27
13
69
9
17
135
4
61
5
24
41
1937
1034
903
min.
min.
min.
Number of
frames
652
566
195
715
311
Depth,
(m)
25.5
17.0
16.7
16.0
16.0
27.0
6.0
5.8
9.9
6.0
7.0
9.0
9.0
8.8
19.0
19.0
19.0
19.0
13.5
12.0
30.4
10.2
18.3
8.2
11.0
12.4
12.0
12.0
12.0
12.0
12.0
14.0
487
108
3034
frames
18.3
13.7
11.7
14.0
17.5
16.2
16.0
10.6
13.9
14.0
15.0
14.9
14.1
m
Temperature (°C)
air
water
15.5
12.9
19.5
13.4
23.7
14.0
23.7
14.0
23.7
14.0
23.7
14.0
12.0
10.0
12.0
10.0
12.0
10.0
12.0
10.0
12.0
10.0
12.0
10.0
12.0
10.0
12.0
10.0
20.0
14.0
21.1
13.5
21.1
13.5
21.1
13.5
21.1
13.5
21.1
13.5
20.0
10.5
20.0
10.5
15.8
10.0
15.8
10.0
14.0
10.3
14.0
10.3
14.0
10.3
14.0
10.3
14.0
10.3
13.0
11.8
13.0
11.8
13.0
11.8
13.0
11.8
14.1
8.6
13.2
10.8
13.2
10.8
13.2
10.8
13.2
10.8
13.2
10.8
13.2
10.8
13.2
10.8
13.2
10.8
14.1
8.9
14.1
8.9
14.1
8.9
14.1
8.9
15.7
11.2
degrees
degrees
Page 35
Offshore feeding area, northeast Sakhalin Island, 2003.
Date
8/7/2003
8/27/2003
8/28/2003
9/5/2003
9/6/2003
9/7/2003
9/8/2003
9/9/2003
9/10/2003
9/13/2003
10
days
Duration, (min.)
Mission Sighting
Number
Number of
number
number of w hales Mission Sighting Trip
frames
1
1
2
83
32
31
412
1
2
1
20
2
1
3
142
44
72
2
2
3
26
1
1
1
167
74
39
412
1
2
1
54
2
1
2
170
45
87
2
2
2
14
2
3
1
24
1
1
2
185
54
126
450
1
2
1
3
1
3
1
2
2
1
4
250
136
114
3
1
1
105
24
73
3
2
3
8
1
1
4
72
55
17
727
2
1
2
157
10
70
2
2
1
8
2
3
2
69
3
1
1
154
9
60
3
2
1
14
3
3
1
71
1
1
1
148
105
43
58
2
1
1
50
22
28
1
1
1
110
13
37
281
1
2
3
60
2
1
1
173
33
67
2
2
2
73
3
0
0
77
0
77
1
1
1
325
31
244
125
1
2
1
20
1
3
1
30
1
1
1
85
37
48
18
1
1
2
177
78
78
313
1
2
1
21
1
1
3
150
52
50
341
1
2
1
48
2
1
2
112
76
36
3
1
3
110
14
81
3
2
1
15
21
40
66
3002
1524
1478
3137
missions sightings w hales
min.
min.
min.
frames
Depth,
(m)
51.7
52.3
48.0
51.1
55.0
58.5
56.0
50.0
44.1
44.1
46.0
47.1
50.0
56.0
52.8
54.2
55.0
53.3
56.7
54.0
56.0
46.6
46.0
56.8
54.7
54.2
60.5
n.d.
54.8
64.2
60.7
49.2
53.7
52.8
47.7
46.3
49.8
49.6
47.0
52.3
m
Temperature (°C)
air
w ater
16.0
8.4
16.0
8.4
18.2
13.0
13.0
13.0
13.0
13.0
13.1
13.3
13.3
20.4
19.7
19.7
16.9
14.1
14.1
14.1
19.8
19.8
19.8
17.1
12.8
15.8
15.8
19.3
19.3
19.6
17.4
17.4
17.4
18.0
16.7
16.7
15.5
15.5
15.1
15.2
15.2
16.2
degrees
11.0
11.0
10.5
10.5
10.5
11.3
11.3
11.3
12.3
10.0
10.0
10.9
11.0
11.0
11.0
11.0
11.0
11.0
12.4
11.9
10.5
10.5
11.1
11.1
11.2
11.8
11.8
11.8
12.0
12.0
12.0
10.4
10.4
11.1
10.5
10.5
10.9
degrees
Page 36
Table 5. Descriptive statistics from gray whale photo-id conducted from a zodiac off
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Parameters
Number of survey days
Average depth, m
Average air temperature, °C
Average water temperature, °C
Number of missions
Number of sightings
Total number of whales sighted (field data)
Average number of whales per survey day
Average number of whales per mission
Average number of whales per sighting
Total duration of missions, min.
Total duration of sightings, min.
Transit time to survey area, min.
Number of frames per voyage
Average number of frames per survey day
Average number of frames per mission
Average number of frames per sighting
Average number of frames per whale (field data)
Piltun
Area
7
14.1
15.7
11.2
14
46
80
11.4
5.7
1.7
1937
1034
903
3034
433.4
216.7
65.9
37.9
Offshore Total for
Area
Both Areas
10
17
52.3
33.2
16.2
15.9
10.9
11
21
35
40
86
66
146
6.6
8.6
3.1
4.2
1.6
1.7
3002
4939
1524
2558
1478
2381
3137
6171
313.7
363.0
149.4
176.3
78.4
71.7
47.5
42.3
Page 37
Table 6. Number of aspects photographed for individual gray whales off the northeast
coast of northeast Sakhalin Island, 2003.
Whale
Right
Left
Dorsal
Ventral
Number
number
RGW002
RGW004
RGW005
RGW006
RGW007
RGW008
RGW012
RGW014
RGW015
RGW016
RGW017
RGW019
RGW020
RGW021
RGW022
RGW026
RGW027
RGW028
RGW029
RGW030
RGW032
RGW034
RGW035
RGW037
RGW038
RGW039
RGW040
RGW041
RGW042
RGW045
RGW046
RGW047
RGW048
RGW049
RGW050
RGW051
RGW052
RGW053
RGW054
RGW055
RGW056
RGW057
RGW058
RGW059
RGW060
RGW061
RGW062
RGW063
Side
y
y
y
y
n
y
y
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
Side
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
Fluke
y
y
y
y
y
y
y
y
y
y
y
n
y
y
y
y
n
y
y
n
y
y
y
y
y
n
y
n
y
y
y
n
y
y
n
y
y
y
n
y
y
y
y
y
y
y
n
y
Fluke
y
y
y
y
y
y
y
y
y
y
y
n
y
n
y
y
n
y
y
n
y
n
y
y
y
n
y
y
y
y
y
n
y
y
n
y
y
y
n
y
n
y
y
y
y
y
n
y
of aspects
4
4
4
4
2
4
4
4
4
4
4
1
4
3
4
4
2
4
4
2
4
3
4
4
4
2
4
3
4
4
4
1
4
4
2
4
4
4
2
4
3
4
4
4
4
4
2
3
ID
Efficiency
100%
y
y
y
y
n
y
y
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
Page 38
Whale
Right
Left
Dorsal
Ventral
Number
number
Side
Side
Fluke
Fluke
of aspects
ID
Efficiency
100%
RGW064
RGW065
RGW066
RGW067
RGW068
RGW069
RGW070
RGW071
RGW072
RGW073
RGW074
RGW075
RGW076
RGW077
RGW078
RGW079
RGW080
RGW081
RGW082
RGW083
RGW084
RGW085
RGW086
RGW087
RGW088
RGW089
RGW090
RGW091
RGW092
RGW093
RGW094
RGW095
RGW096
y
y
y
y
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
n
y
y
n
n
n
y
y
y
y
y
y
y
y
y
y
y
n
y
y
y
y
y
y
y
y
y
y
y
y
y
n
y
y
n
n
y
y
y
y
n
n
y
n
y
n
y
y
n
y
y
n
n
y
n
n
n
n
n
y
n
n
n
y
n
n
n
y
n
n
n
n
y
n
n
n
n
y
n
y
y
n
n
y
n
n
n
n
n
n
n
n
y
n
n
n
y
n
n
n
y
n
n
n
n
4
2
2
3
2
4
2
4
3
2
3
3
2
2
3
2
2
2
2
2
4
2
2
2
4
1
2
1
3
1
1
1
1
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
y
n
y
n
y
n
n
n
n
Page 39
Table 7. Group size of gray whale sightings during photo-id along Sakhalin Island, 2003.
______________________________________________________________
1
2
3
4
5
58
38
18
4
2
48.33
31.66
15.00
3.33
1.66
1
2
3
4
5
33
13
10
2
0
56.89
22.41
17.24
3.44
0
1
2
3
4
5
25
25
8
2
2
40.32
40.32
12.90
3.22
3.22
Offshore area
Piltun area
Page 40
Table 8. Frequency of re-sightings of photo-identified gray whales in the Piltun and
Offshore feeding areas off the northeast coast of Sakhalin Island in 2002 and
2003.
Number of gray whale
re-sightings
Whale number
2002
RGW001
RGW002
RGW003
RGW004
RGW005
RGW006
RGW007
RGW008
RGW009
RGW010
RGW011
RGW012
RGW013
RGW014
RGW015
RGW016
RGW017
RGW018
RGW019
RGW020
RGW021
RGW022
RGW023
RGW024
RGW025
RGW026
RGW027
RGW028
RGW029
RGW030
RGW031
RGW032
RGW033
RGW034
RGW035
RGW036
RGW037
RGW038
RGW039
1
3
2
1
2
2
1
1
1
2
1
2
1
1
1
3
1
3
1
1
2
1
1
2
1
2
1
2
2
2
1
2
1
1
1
1
1
1
1
2003
4
2
2
2
1
1
3
3
2
1
1
1
4
2
4
2
2
2
3
1
2
1
2
4
3
1
Page 41
re-sightings
Whale number
2002
2003
RGW040
1
3
RGW041
RGW042
RGW043
RGW044
RGW045
RGW046
RGW047
RGW048
RGW049
RGW050
RGW051
RGW052
RGW053
RGW054
RGW055
RGW056
RGW057
RGW058
RGW059
RGW060
RGW061
RGW062
RGW063
RGW064
RGW065
RGW066
RGW067
RGW068
RGW069
RGW070
RGW071
RGW072
RGW073
RGW074
RGW075
RGW076
RGW077
RGW078
RGW079
RGW080
2
2
1
1
1
1
2
1
4
2
1
2
2
1
1
3
3
2
2
1
1
1
3
1
2
3
2
1
1
1
1
1
3
2
1
1
2
3
1
4
1
3
2
1
Page 42
re-sightings
Whale number
2002
2003
RGW081
1
RGW082
RGW083
RGW084
RGW085
RGW086
RGW087
RGW088
RGW089
RGW090
RGW091
RGW092
RGW093
RGW094
RGW095
RGW096
3
1
1
3
3
1
3
2
2
1
1
1
1
1
1
154 sightings
of 81 individuals
66 sightings
of 47 individuals
Average Number of sighting per whale in 2002 - 1.40
Average Number of sighting per whale in 2003 - 1.90
Page 43
Table 9. Number of re-sightings of photo-identified gray whales in the Piltun and
Offshore feeding areas off the northeast coast of Sakhalin Island, 2003.
Whale number
Feeding Area
Piltun
RGW002
RGW004
RGW005
RGW006
RGW007
RGW008
RGW012
RGW013
RGW014
RGW016
RGW017
RGW019
RGW020
RGW021
RGW022
RGW026
RGW027
RGW028
RGW029
RGW030
RGW032
RGW034
RGW035
RGW037
RGW038
RGW039
RGW040
RGW041
RGW042
RGW045
RGW046
RGW047
RGW048
RGW049
RGW050
RGW051
RGW052
RGW053
RGW054
RGW055
RGW056
RGW057
RGW058
RGW059
RGW060
RGW061
RGW062
RGW063
RGW064
Offshore
4
2
2
2
1
1
3
3
2
1
1
1
4
2
4
2
2
2
3
1
2
1
2
1
2
2
1
2
2
2
2
3
1
2
1
2
2
1
1
3
3
2
2
1
1
1
3
2
2
1
1
2
1
Page 44
Whale number
Feeding Area
Piltun
RGW065
RGW066
RGW067
RGW068
RGW069
RGW070
RGW071
RGW072
RGW073
RGW074
RGW075
RGW076
RGW077
RGW078
RGW079
RGW080
RGW081
RGW082
RGW083
RGW084
RGW085
RGW086
RGW087
RGW088
RGW089
RGW090
RGW091
RGW092
RGW093
RGW094
RGW095
RGW096
Offshore
1
1
1
1
3
2
1
1
2
3
1
4
1
3
2
1
1
3
1
1
3
3
1
3
2
2
1
1
1
1
1
1
85 whale sightings
69 whale sightings
In the Piltun area, 51 individual whales were identified
In the Offshore area, 34 individual whales were identified
There were in total, 154 sightings of 81 individual whales in both the Piltun and
Offshore feeding areas
During the study period, four whales were sighted (RGW037, RGW045, RGW040, RGW062)
in both feeding areas.
Page 45
Table 10. Feeding areas where individual gray whales were observed off northeastern
Sakhalin Island in 2002 and 2003.
Whale number
2002
Piltun/Offshore
2003
Piltun/Offshore
RGW001
2002_09_14
Offshore
RGW002
2002_09_14
2002_09_11
2002_09_23
Offshore
2003_08_27
Offshore
Offshore
Offshore
2003_08_28
2003_09_05
2003_09_08
Offshore
Offshore
Offshore
RGW003
2002_09_14
2002_09_24
Offshore
Offshore
RGW004
2002_09_14
Offshore
2003_08_27
2003_09_06
Offshore
Offshore
RGW005
2002_09_23
Offshore
2003_08_25
2003_09_18
Piltun
Piltun
RGW006
2002_09_16
2002_09_24
Offshore
Offshore
2003_08_24
2003_09_02
Piltun
Piltun
RGW007
2002_09_16
Offshore
2003_08_18
Offshore
RGW008
2002_09_16
2002_10_12
Offshore
Offshore
2003_09_18
Offshore
RGW009
2002_09_16
2002_09_17
Offshore
Offshore
RGW010
2002_09_23
Offshore
RGW011
2002_09_24
Offshore
RGW012
2002_09_24
2002_10_10
Offshore
Offshore
2003_08_18
2003_08_27
2003_09_07
Offshore
Offshore
Offshore
RGW013
2002_09_23
Offshore
2003_08_28
2003_09_05
2003_09_13
Offshore
Offshore
Offshore
RGW014
2002_09_24
Offshore
2003_09_06
203_09_10
Offshore
Offshore
RGW015
2002_09_24
2002_10_11
Offshore
Offshore
RGW016
2002_09_23
2002_09_24
2002_10_11
Offshore
Offshore
Offshore
2003_09_07
Offshore
RGW017
2002_09_24
2002_10_12
Offshore
Offshore
2003_09_04
Piltun
RGW018
2002_09_24
Offshore
RGW019
2002_09_28
Piltun
2003_08_25
Piltun
RGW020
2002_09_17
2002_09_23
2002_09_24
Offshore
Offshore
Offshore
2003_08_07
2003_08_27
2003_09_05
Offshore
Offshore
Offshore
Page 46
Whale number
2002
Piltun/Offshore
2003
Piltun/Offshore
2003_09_08
Offshore
RGW021
2002_09_24
Offshore
2003_08_07
2003_08_18
Offshore
Offshore
RGW022
2002_09_24
2002_10_10
Offshore
Offshore
2003_08_27
2003_08_28
2003_09_05
2003_09_10
Offshore
Offshore
Offshore
Offshore
RGW023
2002_09_27
Piltun
RGW024
2002_09_28
2002_10_07
Piltun
Piltun
RGW025
2002_09_28
Piltun
RGW026
2002_09_28
2002_10_10
2002_10_11
Piltun
Offshore
Offshore
2003_09_07
2003_09_13
Offshore
Offshore
RGW027
2002_09_28
2002_10_07
Piltun
Piltun
2003_08_24
2003_08_25
Piltun
Piltun
RGW028
2002_10_07
Piltun
2003_08_25
2003_09_03
Piltun
Piltun
RGW029
2002_10_11
Offshore
2003_08_24
2003_08_25
2003_09_18
Piltun
Piltun
Piltun
RGW030
2002_10_07
Piltun
2003_09_18
Piltun
RGW031
2002_10_07
Piltun
RGW032
2002_10_07
2002_10_15
Piltun
Piltun
2003_08_15
2003_09_03
Piltun
Piltun
RGW033
2002_10_07
Piltun
RGW034
2002_09_23
2002_09_24
Offshore
Offshore
2003_08_25
Piltun
RGW035
2002_09_23
Offshore
2003_09_05
2003_09_09
Offshore
Offshore
RGW036
2002_09_23
2002_09_24
Offshore
Offshore
RGW037
2002_09_23
Offshore
2003_08_15
2003_09_07
2003_09_13
2003_09_19
Piltun
Offshore
Offshore
Piltun
RGW038
2002_09_23
Offshore
2003_09_05
2003_09_07
2003_09_13
Offshore
Offshore
Offshore
RGW039
2002_10_10
2002_10_12
Offshore
Offshore
2003_08_25
Piltun
RGW040
2002_10_10
Offshore
2003_08_24
Piltun
Page 47
Whale number
2002
Piltun/Offshore
2003
Piltun/Offshore
2003_08_25
2003_09_08
Piltun
Offshore
RGW041
2002_10_10
Offshore
2003_08_25
2003_09_19
Piltun
Piltun
RGW042
2002_10_12
Offshore
2003_09_02
Piltun
RGW043
2002_10_12
Offshore
RGW044
2002_10_15
Piltun
RGW045
2002_09_24
Offshore
2003_08_23
2003_08_25
2003_09_05
2003_09_08
Piltun
Piltun
Offshore
Offshore
RGW046
2002_10_12
Offshore
2003_09_04
2003_09_19
Piltun
Piltun
RGW047
2002_09_17
Offshore
2003_08_28
Offshore
RGW048
200_08_27
2003_09_05
Offshore
Offshore
RGW049
2003_08_28
2003_08_25
Piltun
Piltun
RGW050
2003_09_04
Piltun
RGW051
2003_09_24
Piltun
RGW052
2003_08_13
2003_08_23
2003_08_25
Piltun
Piltun
Piltun
RGW053
2003_08_07
2003_08_29
2003_09_13
Offshore
Offshore
Offshore
RGW054
2003_08_25
2003_09_03
Piltun
Piltun
RGW055
2003_08_28
2003_09_05
Offshore
Offshore
RGW056
2003_09_03
Piltun
RGW057
2003_08_27
Offshore
RGW058
2003_08_24
Piltun
RGW059
2003_08_24
2003_09_03
2003_09_04
Piltun
Piltun
Piltun
RGW060
2003_08_07
Offshore
RGW061
2003_08_07
2003_09_07
Offshore
Offshore
RGW062
2003_09_03
2003_09_04
2003_09_13
Piltun
Piltun
Offshore
Page 48
Whale number
2002
Piltun/Offshore
2003
Piltun/Offshore
RGW063
2003_08_23
2003_08_25
Piltun
Piltun
RGW064
2003_08_24
Piltun
RGW065
2003_09_04
Piltun
RGW066
2003_08_25
Piltun
RGW067
2003_08_25
Piltun
RGW068
2003_09_04
Piltun
RGW069
2003_08_18
2003_08_28
2003_09_10
Offshore
Offshore
Offshore
RGW070
2003_09_03
2003_09_04
Piltun
Piltun
RGW071
2003_09_18
Offshore
RGW072
2003_08_18
Offshore
RGW073
2003_09_03
2003_09_18
Piltun
Piltun
RGW074
2003_08_18
2003_08_28
2003_09_05
Offshore
Offshore
Offshore
RGW075
2003_08_15
Piltun
RGW076
2003_08_13
2003_08_25
2003_09_03
2003_09_18
Piltun
Piltun
Piltun
Piltun
RGW077
2003_08_25
Piltun
RGW078
2003_08_13
2003_09_03
2003_09_04
Piltun
Piltun
Piltun
RGW079
2003_08_25
2003_09_03
Piltun
Piltun
RGW080
2003_08_25
Piltun
RGW081
2003_08_25
Piltun
RGW082
2003_08_15
2003_08_25
2003_09_03
Piltun
Piltun
Piltun
RGW083
2003_08_25
Piltun
RGW084
2003_08_25
Piltun
RGW085
2003_08_25
2003_09_03
2003_09_18
Piltun
Piltun
Piltun
RGW086
2003_08_25
2003_09_03
Piltun
Piltun
Page 49
Whale number
2002
Piltun/Offshore
2003
Piltun/Offshore
2003_09_18
Piltun
RGW087
2003_08_25
Piltun
RGW088
2003_08_14
2003_08_18
2003_08_28
Offshore
Offshore
Offshore
RGW089
2003_08_18
2003_09_07
Offshore
Offshore
RGW090
2003_09_08
2003_09_13
Offshore
Offshore
RGW091
2003_09_18
Offshore
RGW092
2003_08_07
Offshore
RGW093
2003_08_13
Piltun
RGW094
2003_09_18
Piltun
RGW095
2003_08_13
Piltun
RGW096
2003_08_15
Piltun
Page 50
Table 11. Sightings of individual whales, females with calves, body condition, and skin
condition, 2003.
Whale
number
RGW001
RGW002
RGW003
RGW004
RGW005
RGW006
RGW007
RGW008
RGW009
RGW010
RGW011
RGW012
RGW013
RGW014
RGW015
RGW016
RGW017
RGW018
RGW019
RGW020
RGW021
RGW022
RGW023
RGW024
RGW025
RGW026
RGW027
RGW028
RGW029
RGW030
RGW031
RGW032
RGW033
RGW034
RGW035
RGW036
RGW037
RGW038
RGW039
RGW040
RGW041
RGW042
RGW043
RGW044
RGW045
RGW046
RGW047
RGW048
RGW049
2003
Cow/calf
x
x
x
x
x
x
Cow
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Cow
Cow
Cow
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Cow?
Cow
Cow
Cow
Body
condition
Class 0
Class 1
Class 0
Class 0
Class 2
Class 0
Class 0
Class 3
Class 0
Class 0
Class 0
Class 1
Class 1
Class 2
Class 0
Class 0
Class 0
Class 0
Class 2
Class 2
Class 0
Class 0
Class 0
Class 0
Class 0
Class 1
Class 2
Class 3
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 2
Class 0
Class 3
Class 2
Class 0
Class 0
Class 1
Class 2
Class 0
Class 0
Class 0
Skin
condition
m2
m2
m3
m1
m1
Page 51
Whale
number
RGW050
RGW051
RGW052
RGW053
RGW054
RGW055
RGW056
RGW057
RGW058
RGW059
RGW060
RGW061
RGW062
RGW063
RGW064
RGW065
RGW066
RGW067
RGW068
RGW069
RGW070
RGW071
RGW072
RGW073
RGW074
RGW075
RGW076
RGW077
RGW078
RGW079
RGW080
RGW081
RGW082
RGW083
RGW084
RGW085
RGW086
RGW087
RGW088
RGW089
RGW090
RGW091
RGW092
RGW093
RGW094
RGW095
RGW096
2003
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Cow/calf
Calf ?
Cow ?
?
Cow
?
?
Calf ?
?
?
?
Calf
Calf
Calf
Calf
Calf
Calf
Calf
Calf
Calf
Calf ?
Body
condition
Class 0
Class 2
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 2
Class 0
Class 0
Class 0
Class 0
Class 2
Class 0
Class 0
Class 2
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 1
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Class 0
Skin
condition
m2
m2
from m1to m3
m1
Page 52

photo-identification of the korea

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